This is the drive on which a boot sector will be written, which will take the place of the system partition you're currently using. The boot sector will be written to the system partition that you're currently logged on to if no drive is specified.

The boot sector is written to the partition designated C: drive, which is most likely the partition you're presently logged in to. If that's the case, you can run this command without the c: parameter.

When the Windows boot sector is corrupted, Fixboot is utilized. When the boot records are corrupted, it's also used. Fixboot can also be used to create a new boot sector on the system partition. It restores the Windows bootsector's functionality and replaces the default setting.

This is frequently used in conjunction with the programs booting, diskpart, and fixmbr. The new boot sector will be written to the user's current system partition or the system partition that he has specified.